In light of the challenges of the Anthropocene, it is common today for evaluators to propose a systems rather than a program perspective. A program perspective is reproached for its simplicity and linearity, while the systems perspective is praised for its ability to account for complexity and emergence. This article argues that even before the systems perspective appeared on the horizon, the story of program evaluation had been characterized by a confrontation between “simplifiers” and “complexifiers.” It enquires into the lessons that the complexifiers of the evaluation of programs have handed on to evaluators who are facing the current challenges of sustainable development. On the other hand, when analyzing what a systems perspective contributes, the article is alert to the risk that a “holistic” view may ignore lessons complexifiers have to offer. This argument is supported by considering the way in which a systems perspective is understood in the practice of evaluation. Conclusions invite readers to overcome a misleading opposition between the two perspectives and indicate possible cross-fertilization across different units of analysis and approaches.

鉴于人类世的挑战，今天评估者提出一个系统而不是一个项目的观点是很常见的。程序视角因其简单性和线性而受到指责，而系统视角因其能够解释复杂性和出现的能力而受到称赞。本文认为，即使在系统视角出现之前，程序评估的故事就已经以“简化器”和“复杂器”之间的对抗为特征。它探讨了项目评估的复杂性已经传递给面临可持续发展挑战的评估者的经验教训。另一方面，在分析系统视角的贡献时，这篇文章警惕“整体”观点可能会忽视复杂化者必须提供的教训的风险。考虑到在评估实践中理解系统视角的方式，这一论点得到了支持。结论邀请读者克服两种观点之间的误导性对立，并指出不同分析单元和方法之间可能的交叉施肥。